Aldo Malavasi

Movement of Anastrepha fraterculus from native breeding sites into apple orchards in Southern Brazil

We report movements exhibited by adults of Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) from patches of native forests into apple orchards in Southern Brazil. Two mark‐release‐recapture experiments were conducted using wild flies. Released flies behaved as wild unmarked flies, and periods of peak captures of marked adults coincided with those of unmarked ones. In the first experiment (December 94), out of 2154 released adults, 7.1% were recaptured from day 2 through day 20 after release. Captures peaked from day 7–9 after release. Most marked flies (94.7%) were trapped within 200 m of the release point but eight adults (seven females and one male) were captured in traps placed in an apple orchard, 400–800 m from the release point. The vegetation found between forest and orchard consisted of pastures and annual crops. In the second experiment (January 95), a total of 3284 flies was released in an area where native host plants were abundant and located at ca. 900 m from an apple orchard. In all, 37.1% of marked flies were captured, 99.0% of them at a distance of less than 200 m from the release point. Four adults were captured in an apple orchard, 7 to 24 days after release. They may have reached the orchard through a large and continuous area of native forest. Our results unequivocally demonstrate that A. fraterculus adults are able to disperse from native forests where they originate and invade apple orchards, probably foraging for food and oviposition sites.

Mating Behavior of Wild Anastrepha fraterculus (Diptera: Tephritidae) on a Caged Host Tree

The mating behavior of the South American fruit fly, Anastrepha fraterculus (Wiedemann) is described, following release of wild virgin flies onto a field-caged host tree (guava). Sexual encounters and attempted copulations occurred almost exclusively from 0700-0900 hours and were confined to leaf nodes or the bottom surface of leaves, where males stationed themselves, often forming leks, and appeared to emit a sex pheromone which was attractive to virgin females. There were no male visitations or sexual encounters on green guava fruit, even though females, after mating, frequently oviposited there.

OVIPOSITION DETERRING PHEROMONE INAnastrepha fraterculus FLIES

Anastrepha fraterculus (Wiedemann) females were found to deposit a water-soluble, durable, oviposition-deterring pheromone during ovipositor dragging on fruit after egg-laying. We present evidence that the occurrence of pheromone deposition after egg-laying, the amount deposited, and departure from the fruit without additional egg-laying after pheromone deposition are flexible traits inA. fraterculus, varying in expression according to fruit size and other factors. UnlikeRhagoletis, A. fraterculus males were not arrested by the pheromone.

Field Dispersal and Survival of Sterile Medfly Males Aromatically Treated with Ginger Root Oil

ABSTRACT We studied the dispersal behavior and survival of sterile medfly males either treated or not with ginger root oil (GRO), in field conditions, in Petrolina-PE, northeast Brazil, from May 2006 to December 2007 in a sterile insect technique (SIT) program. The tsl strain Vienna 8 from the Ceratitis capitata Wied. (Diptera: Tephritidae), medfly, mass-rearing facility located in Juazeiro-BA, Brazil, was used. The results showed that sterile males either exposed or not to GRO exhibit similar dispersal behavior and postrelease survival. More than 60% of the sterile males, either treated or not treared wth GRO, were recovered at a 25-m distance from the releasing point, ≈20% at 50 m, and 5% in traps situated 100 m from the releasing point. Around 90% of the sterile males, exposed or not to GRO, were recovered 5 d after release of the sterile male individuals, whereas <1% were recovered after 11 d. Our results imply that ginger root oil can be used to treat sterile medfly males without interfering with their dispersal or survival in the field.

Oviposition behavior of Anastrepha fraterculus in apple and diel pattern of activities in an apple orchard in Brazil

The oviposition behavior and diel pattern of activities of Anastrepha fraterculus (Wied.) (Diptera: Tephritidae) were observed in an apple orchard and fruit characteristics involved in oviposition preferences were investigated in field cage tests. Fruit size influenced fruit acceptability as an oviposition site by females which did not discriminate among the cultivars ‘Gala’, ‘Fuji’, and ‘Golden Delicious’ when same‐size fruits were presented simultaneously. Oviposition behavior in apples was basically the same as that described for primary hosts. Hourly census of fly activity indicated that adults did not overnight in the orchard and that they entered the orchard around 1100 h when temperature reached about 21 °C. Bird droppings were an important food item for adults. Behavioral differences between males and females might account for a significant biased sex ratio both in the orchard and at the edge of the native surrounding vegetation. Implications for fruit fly management in Brazilian apple orchards are discussed.

FIRST REPORT OF CERATITIS CAPITATA (DIPTERA : TEPHRITIDAE) IN THE EASTERN AMAZON, PARA, BRAZIL

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Occurrence and Distribution of Anastrepha in Melon Production Areas in Brazil

There are 78 species of Anastrepha in Brazil (Zucchi, 1988), out of 193 reported by Norrbom (1985). These species infest preferably native fruits and are distributed throughout the country (Malavasi et al., 1980). Three Anastrepha species occurring in Brazil, A. fraterculus, A. obliqua, and A. sororcula, might be considered of economic importance. They cause damage to commercial fruits and their geographical distribution is wide.

Mating and Oviposition Behavior of Anastrepha grandis Under Laboratory Conditions

Anastrepha grandis (MacQuart, 1846) females lay their eggs in cucurbits such as pumpkin and squash. The larvae feed on the fleshy parts of fruits damaging them to human consumption or industrialization. This species is considered a quarantine pest by the USDA. Its distribution in Brazil is restricted to the southern and southeastern regions (Silva et al., 1968). According to Norrbom (in press), this species also occurs in northern Argentina, Paraguay and along the Andean Cordillera from Bolivia to Venezuela.