ABSTRACT Larvae of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) can cause complete defoliation of Lagenaria siceraria (Molina) Standl., commonly known as bottle gourd, resulting in substantial yield losses in India. Female moths oviposit exclusively on the abaxial leaf surface, rather than the adaxial leaf surface, suggesting that abaxial leaf surface wax (ABLSW) chemicals serve as a short‐range attractant and cues for oviposition‐site selection. This study investigates the role of ABLSW chemicals, specifically alkanes and free fatty acids (FFAs), from three bottle gourd cultivars—ANKUR AMIT (AMIT), KSP‐1720 (KSP) and ANKUR GOLU (GOLU)—as short‐range attractants and cues for oviposition‐site selection by H. armigera females. Twenty n ‐alkanes ( n ‐C 14 to n ‐C 36 ) were identified in both adaxial and abaxial leaf surface waxes of these three cultivars. In the adaxial leaf surface waxes (ADLSW), 14 and 13 FFAs within the range of C12:0 to C22:0 were detected in AMIT and KSP, and GOLU, respectively. In contrast, in the ABLSW, 13 and 14 FFAs were detected in AMIT and GOLU, and KSP, respectively. In the ABLSW chemicals, heptadecane and palmitoleic acid were the predominant n ‐alkane and FFA, respectively, in these cultivars. Females exhibited attraction and oviposition on 0.25 leaf equivalent of crude ABLSW from these cultivars compared to solvent controls (petroleum ether), as demonstrated by Y‐tube olfactometer and oviposition assays. Synthetic blends replicating the composition of 0.25 leaf equivalent of crude ABLSW—comprising heptadecane, pentacosane, heptacosane, palmitoleic acid and stearic acid for AMIT; hexadecane, heptadecane and palmitoleic acid for KSP; and heptadecane, palmitoleic acid and stearic acid for GOLU—functioned as candidate active compounds for short‐range attraction and cues for oviposition‐site selection in H. armigera . Females displayed comparable egg‐laying responses to all three synthetic blends when tested against each other. Therefore, these blends may serve as effective lures for baited traps in pest management strategies.
ABSTRACT Drosophila suzukii Matsumura (Diptera: Drosophilidae) is a worldwide invasive pest of soft‐skinned fruits. In this study, we evaluated an attract‐and‐kill (A&K) method using a slow‐release matrix, SPLAT (Specialized Pheromone and Lure Application Technology), formulated with attractants tailored for D. suzukii and spinosad as an alternative strategy to chemical control management strategies. We conducted trials in vineyards and cherry orchards, two commodities that are frequently affected by D. suzukii in northern Greece. The results showed that the A&K treatments reduced D. suzukii populations compared to control plots as assessed by trap catches. In the treated plots, the population remained constant, while in the control plots, the number of individuals increased. The potential of A&K as an ecologically friendly approach to D. suzukii management in Greek orchards is highlighted by this study.
ABSTRACT Methyl eugenol trapping is widely used to monitor male Bactrocera , but capture patterns can reflect crop context, geography, elevation and surrounding landscape as well as species biology. We analysed a harmonised dataset from nine apple, nine guava and nine citrus orchards in East Java, Indonesia, using nine traps per orchard in two sampling periods (486 trap‐period observations). Among 16,185 males, Bactrocera carambolae Drew & Hancock represented 57.6% of apple captures, whereas Bactrocera dorsalis (Hendel) represented 71.9% of guava and 94.8% of citrus captures. Repeated‐measures negative‐binomial models showed markedly higher B. carambolae captures in apple than in guava or citrus, while absolute B. dorsalis captures did not differ among crop systems and sampling period had no overall effect. Crop system explained substantial variation in elevation ( R 2 = 0.742), plant age and latitude. Accordingly, the crop association detected by simple PERMANOVA ( R 2 = 0.269, p = 0.0012) weakened after conditioning on broad geography ( p = 0.0618) or elevation ( p = 0.0682). A pre‐specified AICc candidate set identified crop‐only as the highest‐ranked model for B. carambolae , whereas landscape‐configuration models ranked slightly above crop‐only for B. dorsalis and total captures; these rankings were not robust to leave‐one‐orchard‐out and spatial‐covariance sensitivity analyses. Bactrocera umbrosa (Fabricius) occurred in eight of nine guava orchards but was absent from citrus. These results support context‐aware trap surveillance while showing that lure‐based crop associations should not be interpreted as confirmed host use, infestation or crop damage.
ABSTRACT Plum curculio, Conotrachelus nenuphar (Herbst), is a native fruit pest. Adults emerge from overwintering sites in wooded areas and disperse into crop fields in the spring. However, their movement patterns within fields after this initial dispersal remain poorly understood. In this study, we used protein markers to investigate the in‐field dispersal of C. nenuphar adults in peach ( Prunus persica L.) and highbush blueberry ( Vaccinium corymbosum L.) fields. Chicken egg albumin (egg whites) was applied along field borders and bovine casein (cow's milk) within field interiors. Adults were collected daily using beat sampling, and enzyme‐linked immunosorbent assays (ELISA) were used to detect egg and/or milk proteins on individual insects. This approach provided a form of behavioural forensics, allowing us to trace each insect's movement within the field. Results indicated a strong edge effect in both crops, with 64.3% and 78.0% of adults collected along the border in blueberry and peach, respectively. However, adults collected from interior areas were significantly more likely to be marked with both proteins, suggesting they had dispersed inward through the border rows but rarely returned outward. These findings reveal a consistent colonisation pattern in both crops, where C. nenuphar populations initially establish along field edges before gradually moving into the interior. This provides a behavioural basis for implementation of border‐based management strategies, which could reduce insecticide use through targeted applications while maintaining effective control of C. nenuphar .
ABSTRACT Thrips parvispinus (Karny) has recently become an important invasive thrips in crops world‐wide. It is highly polyphagous and a threat to both ornamental and vegetable crops. Often, new pests are controlled with chemical pesticides, but sustainable options such as biological control are in increasing demand as alternatives. Because prepupae and pupae of this pest occur in the litter layer of the soil, the aim of this work was to test the biological control potential of two belowground predatory mites, Stratiolaelaps scimitus (Berlese) and Macrocheles robustulus (Berlese) in the presence or absence of the nematode Panagrellus redivivus as alternative food supplied to the predators in the soil. Both predators significantly reduced densities of T. parvispinus on sweet pepper plants irrespective of the presence of the nematodes in the soil, however, they did not significantly reduce plant damage. Perhaps combining these predators with an aboveground natural enemy may result in more effective control of T. parvispinus .
