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After being discovered in Taiwan for the first time in June 2019, the polyphagous invasive fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae), has since spread throughout the entire nation. In Taiwan, this insect has a significant impact on the quality and output of wheat, corn, sorghum, and millet. It may further infest more crops in Taiwan due to its diverse range of hosts and alternate hosts. Maize and other staple crops have already been the subject of several study. The biology of FAW has not yet been studied in relation to the alternative hosts, particularly those commonly found in Taiwanese farmlands. Therefore, this study proposed to investigate the effects of napier grass (Pennisetum purpureum), natal grass (Melinis repens), and sunn hemp (Crotalaria juncea) on the development, reproduction, survivorship, and population growth of FAW under laboratory conditions. According to the results, the developmental duration was considerably the shortest when FAW was reared on sunn hemp while the longest on natal grass. Furthermore, female adults reared on napier grass had a longer adult pre-oviposition period, total pre-oviposition period, oviposition period, longevity, highest fecundity, and highest net reproductive rate (Ro: 465.12). Among the tested three alternative host plants evaluated, sunn hemp had the highest intrinsic rate of increase (r: 0.1993), finite rate of increase (λ: 1.2206), and shortest mean generation time (T: 29.98). Therefore, this study suggests that all hosts plants can contribute to the development and outbreak of this pest in the absence of its primary host; however, sunn hemp was a relatively more suitable host plant for this insect. The possibilities for the FAW’s growth and development vary depending on the host plant. Thereby, all potential host plants in the area should be extensively examined while developing an IPM program against FAW.

Although Telenomus remus, a promising parasitoid of Spodoptera frugiperda, had been successfully reared on the eggs of Corcyra cephalonica in some countries, reports from China have argued that it is infeasible. Notably, studies from China have indicated that Spodoptera litura eggs could be a candidate host. Therefore, to further evaluate the potential of using S. litura eggs as hosts, we compared the development and parasitism of T. remus on the eggs of S. frugiperda and S. litura at temperatures between 20–32 °C. Our results showed that T. remus developed successfully on both host eggs at all of the tested temperatures, and the developmental duration and thermal requirements at each stage were similar between the two host species. The number of parasitized eggs was greater for S. litura than for S. frugiperda. Meanwhile, the emergence rate exceeded 86.6%, and it was significantly higher for S. litura than that for S. frugiperda, except at 29 °C. This study is the first time estimating the thermal requirements of T. remus at each stage. Moreover, we also recorded the morphological characteristics of T. remus at each stage. Our results demonstrate that S. litura eggs are more suitable than S. frugiperda eggs as an alternative host for the mass-rearing of T. remus in China. Understanding the thermal requirements and biological parameters contributes greatly to predicting the generation time and providing a reference for the mass-rearing and storage of the parasitoid.

So far, Phenacoccis manihoti (Hemiptera: Pseudococcidae) has been reared mainly with cassava. To explore alternative host plant for rearing of P. manihoti and its parasitoid Anagyrus lopezi De Santis (Hymenoptera: Encyrtidae), we examined suitability of taro Colocasia esculenta (L.) (Alismatales: Araceae) for rearing them in the laboratory, which was compared with that of cassava seedling. Either 50 newly hatched mealybug nymphs or parasitized third-instar mealybugs were reared on taro or cassava seedlings to examine immature development, fecundity and longevity of adults. Nearly 90% of P. manihoti reared on taro successfully developed to adults and they produced 230 eggs on average in their lifetime, while insects reared on cassava showed 95% survival and 250 eggs of lifetime fecundity. For A. lopezi, immature survival was 86% and they laid 140 eggs on average on taro, while it was 88% and 140 eggs on cassava. The results suggested that taro can be used for rearing of P. manihoti and its parasitoid A. lopezi.

Banana bunchy top is one of the most damaging diseases in banana cultivation. However, the distribution and molecular diversity of banana bunchy top virus (BBTV) as well as its alternative hosts in Indonesia have not been reported since 1998. A total of 257 banana leaf samples were collected from the islands of Sumatra, Java, Kalimantan, Sulawesi, Maluku, Papua, Bali, Sumbawa, Timor, and Sumba from 2016 to 2019. The BBTV was detected through PCR in samples from all islands except Kalimantan. A molecular analysis showed that all BBTV isolates belonged to the South East Asian (SEA) subgroup. Based on the DNA-S and DNA-C analysis, the isolates from Sulawesi and Halmahera islands were closely related to those from the Philippines, while the remaining isolates were highly similar to those previously reported from Sumatra, Java, and Bali. Natural infection of BBTV was also recorded on abaca (Musa textilis), wild banana (M. acuminata subsp. sumatrana), ornamental pink banana (M. velutina), galangal (Alpinia galangal), and turmeric (Curcuma longa).

During a survey on insect egg parasitoids in Uşak province (Turkey), parasitized egg clusters of Chlorochroa juniperina (L.) (Hemiptera: Pentatomidae) were collected on Juniperus oxycedrus L. (Cupressaceae). After emergence, the egg parasitoid was identified as Trissolcus semistriatus Nees (Hymenoptera: Scelionidae). This is the first record of this parasitoid reared from the egg masses of C. juniperina. This species has not been previously reported for T. semistriatus as a host species. Mainly eggs of Eurygaster spp. and different pentatomid species were used as hosts in mass culture of the parasitoid. Eggs of this species are acceptable as an alternative host to T. semistriatus during the summer. During 2016 and 2017, 61 egg clusters were collected for the first year and 83 egg clusters were collected for the second year. They have been determined to be parasitized by 31% and 27%, respectively, over the years. Also the rate of emergence and sex ratios were calculated as 98% and 79% in the egg clusters. According to these results, T. semistriatus has an important effect on the populations of C. juniperina under natural conditions in Uşak province of Turkey.

Weeds in agricultural landscapes can serve as alternate hosts for phytopathogenic fungi and promote the spatial and long-term distribution of these fungi. Especially, semi-natural habitats such as kettle holes are considered as a source of fungal pathogens because they are a permanent habitat for various weed species in arable lands. In our study, we investigated the suitability of nine different weed species and families at the edges of 18 kettle holes in two consecutive autumn/winter seasons as alternate hosts for Fusarium and Alternaria. We detected a fungal infestation with both genera on every weed species investigated with significantly higher abundances of these fungi in the second, notably wetter season. Eight weed species were described as non-host plants for Fusarium and Alternaria in agricultural landscapes in Brandenburg, Germany for the first time. In both autumn/winter periods, weeds harbored more Alternaria than Fusarium. The study revealed a high Fusarium species diversity in weeds and a community structure of up to 12 Fusarium species at the edges of kettle holes. Grasses showed the highest diversity and often the highest fungal abundances compared to herbaceous plants. Therefore, these habitats in arable lands can act as ecosystem disservice and promote the spread of fungal diseases in the surrounding crop fields.

Cotton leaf curl disease (CLCuD) is a major constraint in the production of cotton crop across the Africa and Asia which is caused by a complex of begomoviruses (family Geminiviridae). Cotton leaf curl Khokhran virus and associated Cotton leaf curl Multan betasatellite (CLCuKoV/CLCuMB) complex are important agents of CLCuD which transmitted by whiteflies of the Bemisia tabaci species complex. Information regarding the transmission efficiency of CLCuKoV/CLCuMB by whitefly cryptic species is seriously lacking in Pakistan, therefore present study is conducted for comparison of transmission efficiency of CLCuKoV/CLCuMB by two characterized whitefly cryptic species (Asia II-1 and Asia II-5). Whitefly cryptic species were reared separately on Nicotiana benthamiana plants infected with CLCuKoV/CLCuMB for 24 or 48 h and these infected whitefly cryptic species were transferred to un-infected cotton and alternative host plants for 24 or 48 h. The first experiment results showed that Asia II-1 was able to transmit CLCuKoV/CLCuMB with high efficiency in cotton and bitter gourd plants as compared to the Asia II-5 while other host plants did not develop symptoms. Further in the second experiment results revealed that Asia II-1 was able to transmit CLCuKoV/CLCuMB with high efficiency from symptomatic bitter gourd to cotton plants as compared to Asia II-5 which did not show symptoms of transmission. Infection symptoms were confirmed by visual inspection after 30 days and PCR analysis. We found the percentage of virus infection symptoms in alternate host plants differed between two whitefly cryptic species due to varying transmission efficiencies. This research finding advances our understanding to explore the whitefly cryptic species involved in the transmission of CLCuD and will aid in the development of management strategies for control of whitefly cryptic species and CLCuD transmission in Pakistan.

Screening for a new yeast as an alternative host is expected to solve the limitations in the present yeast expression system. A yeast sample which was isolated from the traditional food starter ‘ragi’ from Malaysia was identified to contain Meyerozyma guilliermondii strain SMB. This yeast-like fungus strain SMB was characterized to assess its suitability as an expression host. Lipase activity was absent in this host (when assayed at 30 °C and 70 °C) and Hygromycin B (50 μg/mL) was found to be its best selection marker. Then, the hyg gene (Hygromycin B) was used to replace the sh ble gene (Zeocin) expression cassette in a Komagataella phaffii expression vector (designated as pFLDhα). A gene encoding the mature thermostable lipase from Bacillus sp. L2 was cloned into pFLDhα, followed by transformation into strain SMB. The optimal expression of L2 lipase was achieved using YPTM (Yeast Extract-Peptone-Tryptic-Methanol) medium after 48 h with 0.5% (v/v) methanol induction, which was 3 times faster than another K. phaffii expression system. In conclusion, a new host-vector system was established as a platform to express L2 lipase under the regulation of PFLD1. It could also be promising to express other recombinant proteins without inducers.

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is the vector of the pathogen presumably responsible for causing huanglongbing, a devastating disease affecting citrus (Sapindales: Rutaceae). It is well established that D. citri populations decrease significantly during winter because of the diminution of young emerging leaves, which are the only site of egg laying and nymphal development. Therefore, this period could be a weak link in the phenology of D. citri, and populations appear to be more sensitive to responsive actions such as insecticide sprays. However, little is known about the distribution of D. citri adults within citrus orchards during winter. We surveyed populations of D. citri in commercial citrus groves in central Florida over the course of 2 yr. In 4 groves, we sampled the citrus canopy at 3 heights and at the 4 cardinal directions. We also investigated the potential for alternative habitats for D. citri and sampled non-crop vegetation and potential alternative hosts over 2 seasons. We did not find a consistent pattern in the distribution of D. citri adults during winter in citrus, with one exception; canopies facing south harbored more psyllids than those facing north. We found that the presence of young emerging leaves was the major factor driving D. citri population increases during winter, but the abundance of D. citri adults was also positively correlated with relative humidity. We also found that the proportion of psyllids with the green-blue morphotype (the morph with greatest dispersal capability and likely the major driver of spring grove infestations) increased after insecticide application and after cold weather. Finally, we investigated the potential existence of alternative hosts on which D. citri could feed and/or reproduce in the absence of young emerging citrus leaves during winter. We did not find evidence of an alternative host during winter for D. citri in central Florida.

Heraclides anchisiades capys (Lepidoptera: Papilionidae), Citioica anthonilis (Lepidoptera: Saturniidae), and Methona themisto (Lepidoptera: Nymphalidae) are tree and shrub pests commonly found in urban areas. The parasitism capacity of Palmistichus elaeisis (Hymenoptera: Eulophidae) was evaluated on pupae of these lepidopteran pests as well as on 2 commonly used alternative hosts, Anticarsia gemmatalis (Lepidoptera: Noctuidae) and Tenebrio molitor (Coleoptera: Tenebrionidae). The number of parasitoids produced per mg of host pupal biomass was significantly greater on H. anchisiades capys and T. molitor compared with the other 3 lepidopteran species. The mean number of parasitoids emerging per host pupa was also significantly more on H. anchisiades capys compared with C. anthonilis, M. themisto, A. gemmatalis, or T. molitor. All host species tested in this study show the potential to be used in mass rearing P. elaeisis in the laboratory. However, the lower parasitism and emergence of P. elaeisis on H. anchisiades capys pupae suggests that this lepidopteran pest may not be a suitable host for this parasitoid in the field.