Flight Mill Research Articles

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

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.

Photoregime Affects Development, Reproduction, and Flight Performance of the Invasive Fall Armyworm (Lepidoptera: Noctuidae) in China.

The migratory fall armyworm, Spodoptera frugiperda (Smith), has become a worldwide agricultural pest. In this study, the effects of photoregime on the development, reproduction, and flight performance of fall armyworm were assessed based on two-sex life tables, ovarian and testis anatomy, and flight mill tests. The results indicated that photoregime had a significant effect on developmental duration of fall armyworm individuals, pupal survival and emergence, and adult fecundity. Among seven photoregimes tested, the 16:8 (L:D) h photoregime was the most suitable for fall armyworm fitness with the shortest pre-oviposition period and mean generation period (T), highest mating frequency and mating rate of female moths, largest intrinsic rate of natural increase (rm) and finite rate of increase (λ), and highest net reproduction rate (R0). Population growth for seven different photoregimes in decreasing order was 16:8 (L:D) h > 8:16 (L:D) h > 12:12 (L:D) h > 10:14 (L:D) h > 14:10 (L:D) h > 0:24 (L:D) h > 24:0 (L:D) h. The ovarian development level, mating frequency, and testis size did not significantly differ between long (16:8 (L:D) h) and short (10:14 (L:D) h) illumination. Photoregime had a significant effect on mass loss during flight of adults, but not on flight velocity, flight duration, and flight distance. These findings can be used to refine laboratory rearing protocols, accurately predict seasonal changes in population dynamics and should help improve regional forecasts and management of the fall armyworm.

Females invest more energy in flight: flight characteristics of Platypus quercivorus (Murayama) revealed by a flight mill

ABSTRACT Dispersal flight is an essential component of the life history of bark and ambrosia beetles. Previous studies have shown considerable variation in flight distance between individual beetles; however, different factors drive this variation between species. Furthermore, when the ecological role of dispersal flight differs between sexes (i.e., males locate hosts and females follow), influencing factors might also vary. Here, we evaluated the factors driving variation in the dispersal flight distance of the ambrosia beetle Platypus quercivorus (Murayama) (Coleoptera: Curculionidae: Platypodinae), which is a vector insect of Raffaelea quercivora, the causal agent of the Japanese oak wilt, and we estimated sex-based differences for each influencing factor. A flight mill was used to measure flight distance, flight duration, and initial and terminal flight speed. Because flight speed was not constant during beetle flight, we estimated both initial and terminal flight speed, and assumed that initial flight speed represents a relative measure of energy allocated to flight. Flight distance was mainly determined by flight duration, with an average flight speed of 4.22 km/h for both sexes. Initial and terminal flight speed affected flight distance; however, these factors had contrasting effects between sexes. Specifically, a simultaneous increase in initial and terminal flight speed by males increased flight distance. In comparison, increased flight distance by females was mainly achieved by increasing the initial flight speed. These different patterns in increased flight speed likely reflect differences in the relative importance of flight in the life history of the two sexes.

Beetles prefer steeply angled crevices: effects of wood surface structure on the initiation of hole boring by Platypus quercivorus

ABSTRACT Japanese oak wilt is caused by the pathogen, which is introduced into oaks by the ambrosia beetle Platypus quercivorus of which male initiates to bore. In the field, the entrance holes of beetles have been observed primarily in bark crevices. We hypothesized that male P. quercivorus initially distinguish the bark surface structure and then determine the hole boring site. To test this hypothesis, we observed the initiation of hole boring behavior by P. quercivorus under laboratory conditions. We prepared pieces of Quercus alba with 21 crevice patterns created by changing the opening angle and gap width. Each wood piece was placed in a plastic case and a male P. quercivorus was introduced into the case following flight in a flight mill. The male beetles were monitored for 30 min and the following three behaviors were recorded: whether the beetle recognized the crevice, whether the beetle stayed in the crevice for more than 30 s, and whether the beetle bored a hole in the crevice. Generalized linear models were constructed to clarify which factors (angle and width) influencing beetle behavior. Model analysis revealed that gap width affected only the staying behavior, whereas the opening angle affected all three behaviors. The probabilities of these behaviors occurring increased with a decrease in opening angle, though this trend was weak in hole boring behavior. Our results indicate that P. quercivorus detects a suitable surface structure and subsequently determines the best hole boring site based on structural characteristics, particularly the angle of the crevice opening.

Platypus quercivorus ambrosia beetles use leaf volatiles in host selection

AbstractAlthough chemical volatiles emitted from host and non‐host trees have been suggested as important cues for bark and ambrosia beetles, their responses to leaf volatiles is poorly understood. The oak ambrosia beetle, Platypus quercivorus (Murayama) (Coleoptera: Curculionidae), is a vector for the fungus that causes Japanese oak wilt. Using a Y‐tube olfactometer, we tested the behavioral response of P. quercivorus to leaf volatiles emitted from four host trees – Quercus crispula Blume, Quercus serrata Murray, Quercus salicina Blume, and Castanea crenata Sieb. & Zucc. (all Fagaceae) – and two non‐host trees, Fagus crenata Blume (Fagaceae) and Cryptomeria japonica D. Don (Cupressaceae). A flight mill was used to evaluate the effect of flight on the behavioral response to leaf volatiles. The bioassays were repeated 10× before and 10× after flight in the flight mill for each of the 54 individual beetles. Leaf volatile components were analyzed using gas chromatography–mass spectrometry. The bioassay results supported our hypothesis: P. quercivorus was attracted by the leaf volatiles of hosts and was deterred by the leaf volatiles of non‐hosts. The behavioral response of P. quercivorus to the leaf volatiles was stronger after flight. Males had a stronger behavioral response than females to leaf volatiles. The leaf volatile chemical profile of the non‐host C. japonica differed from the profile of the host plants. However, the chemical profile of the non‐host F. crenata was similar to the profile of the hosts. Our findings provide insight into the functions of leaf chemical volatiles in the interaction of P. quercivorus with its hosts and non‐hosts and may help improve the control of P. quercivorus and Japanese oak wilt.

Effect of Environmental Conditions on Flight Capacity in Mountain Pine Beetle (Coleoptera: Curculionidae: Scolytinae)

Mountain pine beetle (Dendroctonus ponderosae Coleoptera: Curculionidae: Scolytinae) is a major pest of pine (Pinaceae) in western North America. Mountain pine beetle has an obligatory dispersal phase during which beetles fly in search of new hosts to colonize. Climatic factors may influence dispersal in the expanding geographic range of the mountain pine beetle. This study tests mountain pine beetle flight capacity in the laboratory under different abiotic conditions including temperature, light and wind speed. Beetle flight capacity was tested under different temperatures before and during flight and different light regimes in separate computer-linked flight mill bioassays. A wind tunnel experiment tested the effect of wind speed on beetle flight. Pre-flight temperature and temperature during flight did not affect beetle flight capacity (distance or duration). Beetles do, however, use more energy during flight at high temperatures, which could affect host colonization following dispersal by flight of mountain pine beetle in nature. Beetles fly a greater distance and longer duration during a long (18 h) than short (16 h) photophase, suggesting that increased day length with a northern range expansion could affect beetle flight capacity. Although wind speed does not affect flight probability or duration, it affects the number of flights and flight patterns of mountain pine beetles.

Life-History Traits and Flight Capacity of Grapholita molesta (Lepidoptera: Tortricidae) Using Artificial Diets With Varying Sugar Content.

Successful application of the sterile insect technique (SIT), an environmentally friendly control technology, mainly depends on mass-rearing of high-quality and high-performance insects. For mass-rearing of insects, the development of artificial diets is a key component. For optimal insect growth and development, sugar is an essential nutrient as it provides energy for flight. To date, few studies have analyzed the effects of different sugar contents on the biological parameters, including the flight capacity of Grapholita molesta, a globally important economic pest. Artificial diets with different sucrose contents (0, 15, and 30 g) were evaluated in two consecutive generations. The insect flight mill was used to study the G. molesta flight capacity. The larval and pupal periods, adult longevity and pupal weight of the first-generation of G. molesta reared on artificial diets with different sucrose contents were significantly different. Insects of the second-generation had a shorter larval period, greater adult longevity, and heavier larvae and pupae in the treatment with 30 g of sucrose than using 15 g. Among the males, strong, medium, and weak flight capacities were recorded and the weakest one was observed in the diet without sucrose. Results showed that the proportion of insects with highest flight capacity increased with increasing sucrose content in insects of the second generation. It can be concluded that sucrose content is a key determinant in the biological traits, including flight capacity of G. molesta, and should be taken into consideration during the mass-rearing of the pest for SIT.

Strong impacts of smoke polluted air demonstrated on the flight behaviour of the painted lady butterfly (Vanessa cardui L.)

1. A major component of biomass burning smoke is fine particulate matter (PM2.5), which has been shown to generate impacts on insect population dynamics and development. However, little is known about its effect on insect flight behaviour, even though this will influence insect dispersal and distribution, and potentially migration and ecosystem services such as pollination.2. Here we use a tethered flight mill setup to examine the behaviour of adult painted lady butterflies (Vanessa cardui L.) flying in different levels of combustion‐generated airborne PM2.5, comparison this to TFM flying under ‘clean air’ conditions.3. Descriptive statistics and paired sample t‐tests indicate that the smoke had a significantly deleterious impact on flight behaviour, with for example total flight distance covered declining by 65% during the first 20 min of flying in the least smoke contaminated air compared to ‘clean air’ control conditions, whilst average speed declined by 54% and flight duration by 32%. A strongly negative and highly significant linear correlation between flight speed and PM2.5 concentration was also observed.4. This study represents the first time that smoke effects on insect flight behaviour have been experimentally tested, and the longer the butterflies were exposed to the elevated PM2.5 concentrations the more obviously their flight behaviour declined. We conclude that the month(s)‐long episodes of air pollution often associated with agricultural burning and deforestation fires in the tropics may well be significantly affecting the behaviour of the flying insects living in those regions and/or who migrate through them.

Effects of diet and temperature on monarch butterfly wing morphology and flight ability

While global change research has greatly expanded in recent years, it remains unclear how environmental change will impact the mobility of many organisms. Flight is an important mode of transportation that affects ecological functions, including mate location, foraging, and migration. However, the effects of increasing temperature and diet quality on flight remain largely unknown. Here, we explore the effects of rearing temperature and larval diet quality on the flight ability of an iconic and ecologically threatened migratory insect, the monarch butterfly, Danaus plexippus. Monarch larvae were reared at two temperatures (25 °C and 28 °C) and on three milkweed species with varying phytochemistry (Asclepias incarnata, Asclepias syriaca, and Asclepias curassavica) in a fully factorial experiment. We tested flight ability using an automated flight mill, which measured cumulative flight distance, duration, and instantaneous velocity. Higher rearing temperatures reduced monarch flight ability, and larval diet quality influenced forewing morphology. Dietary milkweed with higher cardenolide concentrations (A. curassavica) induced shorter, wider forewings whereas milkweed with low to intermediate cardenolides (A. incarnata and A. syriaca) induced longer, narrower forewings, which are considered better for gliding flight used during migration. Our results provide evidence that projected increases in temperature and the subsequent expansion of tropical milkweed (A. curassavica) into the central breeding range of eastern North American migratory monarchs could reduce migration success. Further research is needed to identify mechanisms explaining the effects of diet and temperature on monarch flight ability and fitness, to ensure that appropriate conservation strategies are employed to preserve migratory populations.

Juvenile hormone regulation on the flight capability of Bactrocera dorsalis (Diptera: Tephritidae)

The oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is considered a major economic threat in many regions worldwide. In order to better understand the flight capacity of B. dorsalis and its physiological basis, the functions and regulatory roles of juvenile hormone (JH) in the flight muscle of B. dorsalis were studied under a controlled environment. JH titer of B. dorsalis varied with age and sex. Females have higher JH titers and better flight capabilities than males, given that the increase in JH also corresponded to the ovarian development and maturation in females. The flight duration and distance of both males and females increased with the gradual increase of JH titer after adult emergences. Both JH titer and flight capability peaked in 15-d-old adult and declined subsequently with age. Flight activity stimulated the production of JH as adults flown for 24 h on the flight mills have the highest JH titers compare to adults flown on shorter flight durations. Adults treated with 0.5 µg and 5 µg of JH III were able to fly long durations and long distances, nevertheless when JH titer was too low or too high, it would restrict the flight ability of the fly. The mutual reinforcement of JH and flight activity provides fundamental understanding on the physiological aspects of the flight capability and dispersal, which facilitates strategies for the long-term control of this destructive pest.

Flight capacities of three species of diving beetles (Coleoptera: Dytiscidae) estimated in a flight mill

To understand the life history strategies of diving beetles, it is important to obtain information regarding their flight capacities. We estimated the flight capacities of three dytiscid species in Japan using a flight mill. The mean flight distances of Hydaticus bowringii Clark, 1864, Hydaticus grammicus (Germar, 1827), and Rhantus suturalis (MacLeay, 1825) were 5.16, 1.97, and 0.58 km, respectively. Some individuals flew extremely long distances: 20.01 km in H. bowringii and 12.58 km in H. grammicus. The two representatives of the genus Hydaticus Leach, 1817 overwinter on land, far from water bodies or in the mud near emergent plants on the shore of water bodies; R. suturalis uses various water bodies throughout the year. The differences in overwintering sites may be reflected in the species’ flight capacities.

Genomic evidence for gene flow between monarchs with divergent migratory phenotypes and flight performance.

Monarch butterflies are known for their spectacular annual migration in eastern North America, with millions of monarchs flying up to 4,500km to overwintering sites in central Mexico. Monarchs also live west of the Rocky Mountains, where they travel shorter distances to overwinter along the Pacific Coast. It is often assumed that eastern and western monarchs form distinct evolutionary units, but genomic studies to support this notion are lacking. We used a tethered flight mill to show that migratory eastern monarchs have greater flight performance than western monarchs, consistent with their greater migratory distances. However, analysing more than 20million SNPs in 43 monarch genomes, we found no evidence for genomic differentiation between eastern and western monarchs. Genomic analysis also showed identical and low levels of genetic diversity, and demographic analyses indicated similar effective population sizes and ongoing gene flow between eastern and western monarchs. Gene expression analysis of a subset of candidate genes during active flight revealed differential gene expression related to nonmuscular motor activity. Our results demonstrate that eastern and western monarchs maintain migratory differences despite ongoing gene flow, and suggest that migratory differences between eastern and western monarchs are not driven by select major-effects alleles. Instead, variation in migratory distance and destination may be driven by environmentally induced differential gene expression or by many alleles of small effect.

Why bark beetles roam near and far

![Figure][1] A mountain pine beetle ( Dendroctonus ponderosae ) flying circuits in the flight mill. Bark beetles are the forester's nemesis. Burrowing beneath the bark of trees to feed and lay their eggs, the beetles weed out weakened trees naturally. However, in the rolling lodgepole pine

How Far Can Rhynchophorus palmarum (Coleoptera: Curculionidae) Fly?

The palm weevil, Rhynchophorus palmarum (L.), was first recorded in San Diego County, CA in 2011 and breeding populations were recovered from infested Canary Islands date palms, Phoenix canariensis, in San Ysidro, San Diego County, in 2015. This palm pest presents a significant threat to California's edible date industry as Phoenix dactylifera is a recorded host for this weevil. The flight capabilities of R. palmarum are unknown which limits understanding of rates of natural dispersal. In response to this knowledge deficit, 24-h flight mill trials were conducted with field-collected male and female weevils. A total of 87 weevils (49 females and 38 males) were used in experiments, ~6% failed to fly >1 km in 24 h and were excluded from analyses. Of those 82 weevils flying >1 km in 24 h, the average distance flown by males and females was ~41 and ~53 km, respectively. Approximately 10% of females flew >100 km in 24 h, with two (~4%) females flying >140 km. The maximum recorded distance flown by a male weevil was 95 km. Flight activity was predominantly diurnal and flying weevils exhibited an average weight loss of ~18% while non-flying control weevils lost ~13% body weight in 24 h. The combined flight distances for male and female weevils exhibited a heavy-tailed platykurtic distribution. Flight mill data for R. palmarum are compared to similarly collected flight mill data for two other species of invasive palm weevil, Rhynchophorus ferrugineus (Olivier) and Rhynchophorus vulneratus (Panzer).

Effect of sex, age and morphological traits on tethered flight of Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) at different temperatures

AbstractThe oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is a pest of fruit and vegetable production that has become established in 42 countries in Africa after its first detection in 2003 in Kenya. It is likely that this rapid expansion is partly due to the reported strong capacity for flight by the pest. This study investigated the tethered flight performance of B. dorsalis over a range of constant temperatures in relation to sex and age. Tethered flight of unmated B. dorsalis aged 3, 10 and 21 days was recorded for 1 h using a computerized flight mill at temperatures of 12, 16, 20, 24, 28, 32 and 36 °C. Variations in fly morphology were observed as they aged. Body mass and wing loading increased with age, whereas wing length and wing area reduced as flies aged. Females had slightly larger wings than males but were not significantly heavier. The longest total distance flown by B. dorsalis in 1 h was 1559.58 m. Frequent short, fast flights were recorded at 12 and 36 °C, but long‐distance flight was optimal between 20 and 24 °C. Young flies tended to have shorter flight bouts than older flies, which was associated with them flying shorter distances. Heavier flies with greater wing loading flew further than lighter flies. Flight distances recorded on flight mills approximated those recorded in the field, and tethered flight patterns suggest a need to factor temperature into the interpretation of trap captures.

Baseline Flight Potential of Euschistus servus (Hemiptera: Pentatomidae) and Its Implications on Local Dispersal.

The brown stink bug, Euschistus servus (Say), is a damaging pest of multiple crops in the southeastern United States. In addition to crops, both the weedy field borders and wooded areas of a typical farmscape in this region harbor E. servus host plants, many of which are temporally and spatially limiting in availability or nutritional suitability. Therefore, local dispersal is required so that individuals efficiently track and utilize host resources. This research sought to establish the baseline flight capacity of adult E. servus across the season in relation to body weight, sex, and plant host use with a flight mill system. Across this 2-yr study, among the individuals with a flight response in the flight mill, 90.1% of individuals flew in a range of >0-1 km, with an individual maximum flight distance of 15.9 km. In 2017, mean total distance flown varied across the season. Except for the individuals collected from corn in 2019, during both 2017 and 2019, the highest numerical mean flight potential occurred soon after overwintering emergence and a relatively low flight potential occurred during the cropping season. Individuals collected from wheat, corn, and early season weeds lost a higher proportion of body weight after flight than did individuals from soybean and late season weeds. The baseline dispersal potential information generated from this study can be extrapolated to the farmscape level aiming to develop, plan, and implement E. servus management programs.

Impacts of fluorescent powders on survival of different age cohorts, blood-feeding success, and tethered flight speed of Aedes aegypti (Diptera: Culicidae) females

Fluorescent powders are one of the most common external markers used to study mosquito behavior and ecology. For their reliable and practical use, it is important to evaluate their effect on biological parameters such as survival, blood-feeding, and mobility. We evaluated the effect of five different fluorescent powders (Day-Glo ® ECO Series) on the survival of different age cohorts, blood-feeding success, and tethered flight speed on Aedes aegypti (Linnaeus) adult females. For survival analysis, three cohorts (2–5, 6–9 and 10–13 days old) were marked and mortality recorded until all died. To examine the effect of fluorescent powders on female response to blood-feeding, the proportions of unfed, partially fed, and fully engorged females, after being exposed to host blood under two different time sets (20 and 40 min.), were compared. Their impact on female tethered flight speed was evaluated recording their flight for 30 min. with a flight mill. Survival distributions between treatments were not significantly different within each cohort. Blood-feeding was not significantly different among marked or unmarked females at both times of blood exposure, with the exception of Signal Green-ECO 18 and Ultra Violet- ECO 20 (at 20 and 40 min.), in which a higher proportion of partially fed females was observed compared to control females. In relation to flight performance, no statistically significant difference in mean tethered flight speed (m/s), among marked and unmarked mosquito groups, was observed. Our results indicate that the tested powders and application method have few significant impacts on Ae. aegypti survival, blood-feeding success and flight performance, and are thus suitable for investigations of mosquito biology in the environment.

Assessing the Flight Capabilities of Fed and Starved Allograpta obliqua (Diptera: Syrphidae), a Natural Enemy of Asian Citrus Psyllid, with Computerized Flight Mills

Flight mills were used to investigate flight capabilities of Allograpta obliqua (Say) (Diptera: Syriphidae), an important predator of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), in California. Specifically, distance by which A. obliqua can fly in 24 h, and the effect of sex and feeding treatment (fed or starved) on flight capabilities were investigated. A total of 17 (7 females, 10 males) laboratory-reared flies were flown. There was no significant effect of sex on distances flown. Out of a total of 3,487 flight bouts, 7 consisted of A. obliqua flying 1 to 2 m, and 5 bouts consisted of A. obliqua flying over 5 m. The remaining bouts (99.7%) were less than 1 m and were considered ‘hovering’ because they consisted of extremely short bursts of flight activity (< 10 s). The 5 bouts over 5 m were conducted by 2 fed females, and the mean distance flown and mean flight bout time were 39 ± 13 m and 113 ± 24 s, respectively.

Retinal slip compensation of pitch-constrained blue bottle flies flying in a flight mill.

In the presence of wind or background image motion, flies are able to maintain a constant retinal slip velocity by regulating flight speed to the extent permitted by their locomotor capacity. Here we investigated the retinal slip compensation of tethered blue bottle flies (Calliphora vomitoria) flying semi-freely along an annular corridor in a magnetically levitated flight mill enclosed by two motorized cylindrical walls. We perturbed the flies' retinal slip by spinning the cylindrical walls, generating bilaterally averaged retinal slip perturbations from -0.3 to 0.3 m s-1 (or -116.4 to 116.4 deg s-1). When the perturbation was less than ∼0.1 m s-1 (38.4 deg s-1), the flies successfully compensated the perturbations and maintained a retinal slip velocity by adjusting their airspeed up to 20%. However, with greater retinal slip perturbation, the flies' compensation became saturated as their airspeed plateaued, indicating that they were unable to further maintain a constant retinal slip velocity. The compensation gain, i.e. the ratio of airspeed compensation and retinal slip perturbation, depended on the spatial frequency of the grating patterns, being the largest at 12 m-1 (0.04 deg-1).

Flight Performance of Mamestra brassicae (Lepidoptera: Noctuidae) Under Different Biotic and Abiotic Conditions.

Mamestra brassicae L. is an important, regionally migratory pest of vegetable crops in Europe and Asia. Its migratory activity contributes significantly to population outbreaks, causing severe crop yield losses. Because an in-depth understanding of flight performance is key to revealing migratory patterns, here we used a computer-linked flight mill and stroboscope to study the flight ability and wingbeat frequency (WBF) of M. brassicae in relation to sex, age, temperature, and relative humidity (RH). The results showed that age significantly affected the flight ability and WBF of M. brassicae, and 3-d-old individuals performed the strongest performance (total flight distance: 45.6 ± 2.5 km; total flight duration: 9.3 ± 0.3 h; WBF: 44.0 ± 0.5 Hz at 24°C and 75% RH). The age for optimal flight was considered to be 2–3 d old. Temperature and RH also significantly affected flight ability and WBF; flight was optimal from 23°C to 25°C and 64–75% RH. Because M. brassicae thus has great potential to undertake long-distance migration, better knowledge of its flight behavior and migration will help establish a pest forecasting and early-warning system.