Aphis gossypii is one of the most economically important agricultural pests that cause serious crop losses worldwide, and the indiscriminate chemical application causes resistance development in A. gossypii, a major obstacle to successful control. In this study, we selected the up-regulated expression gene AgJHAMT, which was enriched into juvenile hormone pathway though transcriptome sequencing analysis of the cotton aphids that fed on transgenic cotton lines expressing dsAgCYP6CY3 (the TG cotton). The AgJHAMT gene was overexpressed in cotton aphids which fed on the TG cotton, and its expression profile during the nymphs was clarified. Then, silencing AgJHAMT could advance the developmental period of cotton aphids by 0.5 days compared with control groups. The T and t values of cotton aphids in the dsJHAMT treatment group (6.88 ± 0.15, 1.65 ± 0.06) were significantly shorter than that of the sprayed H2O control group (7.6 ± 0.14, 1.97 ± 0.09) (P < 0.05), respectively. The fast growth caused by AgJHAMT silencing was rescued by applying the JH analogue, methoprene. Overall, these findings clarified the function of AgJHAMT in the developmental period of A. gossypii. This study contributes to further clarify the molecular mechanisms of delaying the growth and development of cotton aphids by the transgenic cotton lines expressing dsAgCYP6CY3.

Aulacophora lewisii Baly (Coleoptera: Chrysomelidae) is an important pest of Luffa acutangula (L.) Roxb. (Cucurbitaceae) in India. Larvae of A. lewisii feed on the roots, while adults consume leaves of L. acutangula. In the current study, effects of three L. acutangula cultivars (Abhiskar, Debsundari, and Jaipur Long) on the life table parameters by age-stage, two-sex approach, and key digestive enzymatic activities (amylolytic, proteolytic, and lipolytic) of the larvae and adults of A. lewisii were determined. Further, nutrients (total carbohydrates, proteins, lipids, amino acids, and nitrogen content) and antinutrients (total phenols, flavonols, and tannins) present in the roots and leaves of three cultivars were estimated. The development time (egg to adult emergence) was fastest and slowest on Jaipur Long (31.80 days) and Abhiskar (40.91 days), respectively. Fecundity was highest and lowest on Jaipur Long (279.91 eggs) and Abhiskar (137.18 eggs), respectively. The intrinsic rate of increase (r) was lowest on Abhiskar (0.0511 day−1) and highest on Jaipur Long (0.0872 day−1). The net reproductive rate (R0) was lowest on Abhiskar (23.32 offspring female−1). The mean generation time (T) was shortest on Jaipur Long (52.59 days) and longest on Abhiskar (61.58 days). The amylolytic, proteolytic, and lipolytic activities of larvae and adults of A. lewisii were highest and lowest on Jaipur Long and Abhiskar, respectively. The lower level of nutrients and higher level of antinutrients influenced higher larval development time and lower fecundity of A. lewisii on Abhiskar than other cultivars. Our results suggest that Abhiskar cultivar could be promoted for cultivation.

Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae), the cactus moth, is native to South America with a widespread distribution in Argentina. The larvae consume the interior of Opuntia spp. (Cactaceae) plants. The moth was used as a biocontrol agent against invasive non-native Opuntia spp. in many countries around the world. The cactus moth arrived unintentionally in Florida, USA, expanded its range and threatened Opuntia-based agriculture and natural ecosystems in southern North America. The insect is also a pest of cultivated O. ficus-indica L. in Argentina. An endemic South American parasitoid, Goniozus legneri Gordth (Hymenoptera: Bethylidae), is used in inundative biological control programmes against lepidopteran pests. The goal of this work was to evaluate G. legneri as a biocontrol agent to be used in inundative releases against C. cactorum. Mortality of C. cactorum by G. legneri was assessed at different spatial scales, as well as the interactions with Apanteles opuntiarum Martínez & Berta (Hymenoptera: Braconidae), a common Argentine natural enemy of C. cactorum. The ability of G. legneri to paralyse, parasitise and kill C. cactorum was confirmed. The paralysis inflicted on C. cactorum larvae reduced larval damage to the plants by 85%. Using two parasitoid species increased the mortality of C. cactorum larvae, but it was highly dependent on the order of their arrival. The combined mortality caused by both parasitoids was higher than a single one, in particular when G. legneri arrived first (56 ± 1%), suggesting asymmetric competition due to the preference of G. legneri attacking previously parasitised larvae. Goniozus legneri has potential as an inundative biocontrol agent of C. cactorum, but its interaction with the classical biocontrol agent A. opuntiarum needs to be considered.

The generalist predatory mite, Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae) is one of the most effective biocontrol agents to control the pests of many crops in indoor cultivations. In this study, the effects of the enriched diets of the second trophic level, i.e. the stored-product mite, Tyrophagus putrescentiae (Schrank) on the performance of N. cucumeris as the third trophic level was determined in a tritrophic system. In the first step, different pollens including almond, maize, date palm, castor bean, saffron, and cattail or different legume flours including pinto bean, lentil, black-eyed pea, chickpea, mung bean and broad bean as enrichment additives were added to the basic diet, i.e. a mixture of wheat bran and flour as a basic diet of T. putrescentiae. In the second step, to reveal the effects of the mentioned additives on the performance of N. cucumeris, the demographic parameters of the predator were determined when it was fed with the prey enriched with the additives. Our results indicated that N. cucumeris had higher performance by feeding on the prey reared on diets enriched by either pollens or legumes compared with the basic diet. Overall, there was no significant difference between pollen grains and some legume flours when the predatory mite was fed with them through its prey. Since legumes are more available and cost-effective food sources than pollens, they can be affordable supplementary diets for the mass rearing of N. cucumeris.

The touchstone of the ‘New Synthesis’ was population cytogenetics –rather than genetics – due to the abundant polymorphic inversions in the genus Drosophila. Grasshoppers were not a material of choice because of their conservative karyotypes. However, nowadays seven species of Acrididae were described for polymorphic centric fusions, five of them in South-America. Leptysma argentina and the likely biocontrol of water-hyacinth Cornops aquaticum are semiaquatic Leptysminae (Acrididae: Orthoptera), polymorphic for centric fusions, supernumerary segments and a B-chromosome. We sought to demonstrate the operation of natural selection on them, by detecting: (I) latitudinal clines; (II) regression on environmental variables; (III) deviation from null models, such as linkage equilibrium; (IV) seasonal variation; (V) comparison between age classes and (VI) selection component analyses. All of them were confirmed in L. argentina, just (I) and (II) in C. aquaticum. Furthermore, the relationship between karyotype, phenotype and recombination was confirmed in both species. Karyotype–phenotype relationship may be due to the body enlargement the fusions are associated with, along with a latitudinal transition in voltinism. Karyotype-related recombination reduction in both species may help explain all fusion clines, although there is probably more than one factor at work. No effects were noticed for a supernumerary segment in L. argentina, but it is ubiquitous and certainly non-neutral. C. aquaticum is poised for introduction in South-Africa as a biocontrol of water-hyacinths; the recent discovery of four more segment polymorphisms may imply more chromosomal markers to make sense of its genetic system.

The social-sexual environment is well known for its influence on the survival of organisms by modulating their reproductive output. However, whether it affects survival indirectly through a variety of cues without physical contact and its influence relative to direct interaction remain largely unknown. In this study, we investigated both the indirect and direct influences of the social-sexual environment on the survival and reproduction of the mite Tyrophagus curvipenis (Acari: Acaridae). The results demonstrated no apparent influence of conspecific cues on the survival of mites, but the survival and reproduction of mated female mites significantly changed, with the females mated with males having a significantly shortened lifespan and increased lifetime fecundity. For males, no significant difference was observed across treatments in their survival and lifespan. These findings indicate that direct interaction with the opposite sex has a much more profound influence on mites than indirect interaction and highlight the urgent need to expand research on how conspecific cues modulate the performance of organisms with more species to clarify their impacts across taxa.

Mosquito-borne diseases have emerged in North Borneo in Malaysia due to rapid changes in the forest landscape, and mosquito surveillance is key to understanding disease transmission. However, surveillance programmes involving sampling and taxonomic identification require well-trained personnel, are time-consuming and labour-intensive. In this study, we aim to use a deep leaning model (DL) to develop an application capable of automatically detecting mosquito vectors collected from urban and suburban areas in North Borneo, Malaysia. Specifically, a DL model called MobileNetV2 was developed using a total of 4880 images of Aedes aegypti, Aedes albopictus and Culex quinquefasciatus mosquitoes, which are widely distributed in Malaysia. More importantly, the model was deployed as an application that can be used in the field. The model was fine-tuned with hyperparameters of learning rate 0.0001, 0.0005, 0.001, 0.01 and the performance of the model was tested for accuracy, precision, recall and F1 score. Inference time was also considered during development to assess the feasibility of the model as an app in the real world. The model showed an accuracy of at least 97%, a precision of 96% and a recall of 97% on the test set. When used as an app in the field to detect mosquitoes with the elements of different background environments, the model was able to achieve an accuracy of 76% with an inference time of 47.33 ms. Our result demonstrates the practicality of computer vision and DL in the real world of vector and pest surveillance programmes. In the future, more image data and robust DL architecture can be explored to improve the prediction result.