# Identify mango and tomato pests, diseases and greenhouse thrips before treatment URL: https://leafwrit.com/us/fruit-crop-pesticide-selection/ Reviewed: 2026-10-29 ## Pesticides used in mango farming: identify the disease before choosing a product Choose mango crop pesticides after identifying the pest or disease and checking the exact product's crop-use directions. Anthracnose affects flowers, young fruit, leaves and twigs. It can also develop during storage of mature fruit. Rain and heavy dew favor the disease. Powdery mildew affects mango leaves, flowers and young fruit, producing whitish powdery growth. Dry spring conditions favor its development. ### Connect stored-fruit symptoms with the orchard If anthracnose symptoms appear after picking, give the diagnostician both the orchard history and the handling details. Insects contribute to mango pollination. When considering treatment during flowering, describe insect activity in the block and check the selected product's pollinator and environmental directions. Use [EPA's pesticide search resources](https://www.epa.gov/ingredients-used-pesticide-products/how-search-information-about-pesticide-ingredients-and-labels) to retrieve product identity and labeling. The APPRIL product listing includes registered sites and target pests. ## Tomato crop pesticides: separate caterpillars from diseases Identify the tomato pest and production system before choosing a pesticide. The following disease and insect descriptions use California crop guidance. ### Tomato fruitworm: inspect eggs and small larvae Tomato fruitworm is also called cotton bollworm or corn earworm. Feeding creates a messy cavity inside fruit. Monitor eggs and small larvae before larger larvae enter fruit, where sprays cannot readily reach them. Combine adult monitoring with egg sampling and inspection of damaged fruit. *Trichogramma* egg parasitoids and other natural enemies can destroy many fruitworm eggs. Assess parasitism and predation before deciding whether treatment is needed. Keep natural-enemy observations beside pest counts in the scouting record. ### Tomato pinworm: inspect mines and leaf shelters Fruit feeding leaves relatively shallow, dry burrows. Inspect foliage for mines and shelters after detecting adult activity. Remove crop residues and manage other solanaceous hosts. Host-free periods are another component of pinworm prevention. ### Distinguish early blight from late blight Early blight usually appears first on older leaves as leathery spots, often with concentric rings. Late blight produces water-soaked leaf areas that enlarge into oily-looking blotches. Gray-white growth can develop on leaf undersides. ### Field and greenhouse powdery mildew Field-grown tomato powdery mildew involves *Leveillula taurica*. It produces yellow blotches, sometimes with white sporulation. Greenhouse and coastal tomato powdery mildew involves *Oidium neolycopersici*, with conspicuous powdery growth on leaf surfaces. State the production environment and affected leaf surface when asking for identification. ## Controlling thrips in greenhouse crops For greenhouse thrips control, identify the species, scout the crop and combine sanitation with compatible biological or chemical measures. **Greenhouse thrips**, *Heliothrips haemorrhoidalis*, and **western flower thrips**, *Frankliniella occidentalis*, are different species. Greenhouse thrips feed slowly on foliage; western flower thrips often hide in flowers, buds and growing tips. ### Obtain a species identification Flower thrips, western flower thrips and chilli thrips can cause greenhouse problems. Adults are difficult to notice in flight, while adults and nymphs can often be found in open blossoms. Inspect those tissues when scouting. Species identification can require microscopic characters. Submit uncertain specimens through Cooperative Extension or the county agricultural office. Record the identification returned by the specialist and use that name when ordering biological controls or reviewing insecticides. Western flower thrips feeding can deform flowers, leaves and shoots. Silvery scars and dark fecal spots can appear on expanded foliage. ### Map the scouting route Use a greenhouse map, magnification, sticky cards and a record system. Record pest identity and location so follow-up inspections revisit the affected benches and crops. Designate trained personnel to maintain the same scouting method. Monitor adult western flower thrips with yellow sticky cards. Follow changes in counts over time and examine plants alongside the cards. Dislodge insects from flowers or foliage onto white paper to inspect them. Keep card position and plant observations identifiable in the record. Treatment tolerance depends on the crop, development stage and customer's tolerance of damage. Review those factors with the adviser before choosing an action threshold for the affected ornamental, vegetable or herb crop. ### Sanitation, exclusion and incoming stock Inspect new plants and propagation material before moving them into production. Evaluate fine screening together with greenhouse ventilation because screens affect air movement. Remove weeds, plant debris and unwanted retained plants from production areas. Contain discarded material so thrips cannot readily disperse from drying plants back into the crop. ### Match biological control to the thrips stage Predatory mites, predatory bugs and entomopathogenic nematodes have different roles in western flower thrips programs. Match the organism to its target life stage and the greenhouse environment. The soil-dwelling predator **Stratiolaelaps scimitus** targets growing-medium stages, including thrips pupae. ### Select insecticides by crop and mode of action The best insecticide for western flower thrips depends on the identified species, crop, pest stage and existing control program. Resistance is a significant problem. Rotate among effective modes of action and combine compatible measures when planning repeated treatments. Western flower thrips have hosts among ornamentals, vegetables, herbs and herbaceous perennials. Include the natural enemies already present in the compatibility review. ### Investigate virus symptoms and assess the result Western flower thrips transmit impatiens necrotic spot virus and tomato spotted wilt virus. Supply the thrips identification and affected crop details with the plant sample. Use follow-up scouting to evaluate control at the same locations. Track both insects and fresh injury after intervention. ## Next step See the [tomato guide](https://ipm.ucanr.edu/agriculture/tomato/) or [greenhouse thrips guidance](https://ipm.cahnr.uconn.edu/managing-western-flower-thrips-on-greenhouse-crops/). Sampling steps are in [plant diagnostic lab sampling](/us/grape-powdery-mildew/), and label reading in [how to read a pesticide label](/us/read-pesticide-label/).