Systemicity is a desirable property for insecticides. Many phytochemicals show good systemic properties and thus are natural sources of novel systemic insecticidal ingredients. Bruceine D, a quassinoid, was identified in Brucea javanica (L.) Merr. and displayed outstanding systemic properties and excellent antifeedant activity against the diamondback moth (DBM, Plutella xylostella L.), beet armyworm (Spodoptera exigua Hübner), and cotton leafworm (Spodoptera litura Fabricius). Its antifeedant effect on third instar larvae of DBM was approximately 6.2-fold stronger than that of azadirachtin. When bruceine D was applied to roots at a concentration of 100 μg/mL for 24 and 48 h, its concentration in flowering Chinese cabbage (Brassica campestris L. ssp. chinensis var. utiliz Tsen et Lee) leaves was 38.69 μg/g (fresh weight, FW) and 108.45 μg/g (FW), respectively. These concentrations could achieve 93.80% and 96.83% antifeedant effects, which were significantly greater than those of azadirachtin. Similar to azadirachtin, bruceine D also posed a potent growth inhibition effect on insect larvae. After feeding with 20 μg/g bruceine D, no pupae were observed. The results demonstrated that bruceine D is an effective botanical insect antifeedant with outstanding systemic properties, causing potent pest growth inhibitory activity.

During precopulatory courtship, male Drosophila typically produce wing vibration to generate species-specific songs before mounting females. Three species in the lini clade of the montium species subgroup have been found to produce species-specific sine song only after mounting and during copulation. Here we investigated and analyzed the courtship behavior of 29 species in the montium subgroup from video and song recordings and measured the duration of wing vibration. We describe a great diversity of courtship behavior in the montium subgroup. The courtship patterns can be categorized into four types in the montium subgroup: 1) type P/C, species with both precopulatory and copulatory courtship, such as D. parvula and D. nikananu, 2) type P-/C, species with sporadic precopulatory and mainly copulatory courtship, such as D. auraria and D. triauraria. 3) type C, species with only copulatory courtship, such as D. tani and D. pectinifera, 4) type C-, species with only very brief copulatory courtship, such as D. rufa and D. asahinai. According to a phylogenetic tree based on sequences of mitochondrial COI and COII, and the nuclear Adh, both precopulatory courtship and copulatory courtship were present in the most basal species D. parvula. Each of two branches in the montium subgroup contains four types of courtship behavior. Type C is present in each sub-branch. These results suggest that the courtship behavior initially involved both precopulatory and copulatory courtship, but that subsequently precopulatory courtship has gradually been lost in the montium subgroup. We suggest reasons why precopulatory behavior might come to be lost in the montium subgroup.

BACKGROUND: As the use of diamide insecticides on corn continues to increase, there is growing concern about their residue levels on corn and dietary risks to populations. In this study, the distribution, dispersion and transfer efficiency of two diamide insecticides (tetrachlorantraniliprole (TCAP) and cyantraniliprole (CNAP)) in different parts of corn and soil were investigated in a 1-year field trial in Guangzhou and Lanzhou using two different application methodsspray and drip irrigation, respectivelyand the dietary risk of the insecticides to different consumer populations was assessed under the two application methods. RESULTS:The results showed that drip irrigation had a longer persistence period than spraying, and there was a hysteresis in the absorption distribution of the agent in different parts of corn, which was gradually transferred to the leaves after absorption from the roots. The average TE 1 (transfer efficiency) and TE 2 were 0.230-0.261 and 1.749-1.851 for TCAP and 0.168-0.187 and 2.363-2.815 for CNAP, respectively. At corn harvest, both TCAP and CNAP were below detectable levels in soil and corn. For different consumer populations, hazard quotients ranged from 0.001 to 0.066 for TCAP and from 0.003 to 0.568 for CNAPboth well below 100%.CONCLUSION: This study indicates that TCAP and CNAP applied by spray or drip irrigation are safe for long-term risk of human intake and also provides guidance for the use of both insecticides in agricultural production to control corn pests, especially in arid and semi-arid areas.