Evidence for facultative migratory flight behavior in Helicoverpa armigera (Noctuidae: Lepidoptera) in India

Abstract

Despite its deleterious impact on farming and agriculture, the physiology and energetics of insect migration is poorly understood due to our inability to track their individual movements in the field. Many insects, e.g. monarch butterflies, Danaus plexippus (L.), are facultative migrants. Hence, it is important to establish whether specific insect populations in particular areas migrate. The polyphagous insect, Helicoverpa armigera (Hübner), is especially interesting in this regard due to its impact on a variety of crops. Here, we used a laboratory-based flight mill assay to show that Helicoverpa armigera populations clearly demonstrate facultative migration in South India. Based on various flight parameters, we categorized male and female moths as long, medium or short distance fliers. A significant proportion of moths exhibited long-distance flight behavior covering more than 10 km in a single night, averaging about 8 flight hours constituting 61% flight time in the test period. The maximum and average flight speeds of these long fliers were greater than in the other categories. Flight activity across sexes also varied; male moths exhibited better performance than female moths. Wing morphometric parameters including forewing length, wing loading, and wing aspect ratio were key in influencing long-distance flight. Whereas forewing length positively correlated with flight distance and duration, wing loading was negatively correlated.

Plasticity of Life-History Traits and Adult Fitness of Fall Webworm in Relation to Climate Change

“…The dispersal ability [49] and flight frequency of insects [50] fluctuate with temperature, and increased temperature will lower the flight ability of insects [51]. In addition, larger wing size individuals flew faster and tended to fly longer distances compared to smaller wing size individuals [52]. The current results showed that adult H. cunea had longer wings under high-temperature rearing conditions.…”

Evolutionary change in flight-to-light response in urban moths comes with changes in wing morphology

“…Effects of urbanization on mobility-related morphology have been found for some organisms, such as Anolis lizards [ 34 , 35 ]. In insects, wing size and aspect ratio are generally considered to play a key role in flight performance and are positively related to acceleration [ 23 ] and dispersal capacity [ 27 , 36 ]. High wing loading leads to increased flight and dispersal capacity, but also to decreased manoeuvrability [ 37 ].…”

Phenotypic variability in the Old World bollworm, Helicoverpa armigera (Hübner) populations in India

“…The grouping pattern of populations based on previous molecular data from the country (Deepa & Srivastava, 2011; Fakrudin et al., 2004; Venkatesan et al., 2016), also shared similarity with the present findings, where we found clear cut differentiation of studied populations into two major clusters. Intermingling of geographically distant populations from northern and central parts of India into a common group was probably due to migration of adult populations from one agro‐climatic zone to another (Jyothi et al., 2021), while the presence of varied topological and temporal barriers in the country might have led to isolation of all the South Zone populations into a separate group. The heavily rugged topography of the South Zone along with the occurrence of heterogeneous crop matrix due to diverse monsoon patterns, are the important factors that possibly restrict the gene flow by partially blocking the spread of this mobile insect northward towards other zones, thereby probably isolating the populations occurring in this zone from others, as also reported by Vijaykumar et al (2008).…”