Neotropical Entomology (2004) 33, 487-492

Viviane R. Chocorosqui and Antônio R. Panizzi (2004)
Impact of cultivation systems on Dichelops melacanthus (Dallas) (Heteroptera: Pentatomidae) population and damage and its chemical control on wheat
Neotropical Entomology 33 (4), 487-492
Abstract: Results of field evaluations indicated that the neotropical pentatomid Dichelops melacanthus (Dallas) is associated with wheat, Triticum aestivum L. In the no-tillage cultivation system, adults and nymphs were mostly found on the soil, near the plant stems and underneath crop residues of the preceding summer crop, usually soybean, Glycine max (L.) Merrill, or corn, Zea mays L. Wheat grown under the conventional cultivation system showed minimal bug attack. D. melacanthus caused substantial damage to no-tillage wheat plants, particularly to seedlings. Bug attack reduces the number of seed heads of up to 34%. Seed yield was reduced in 31% due to the bugs' feeding, compared to plants free of damage. All developmental phases of the wheat plant were susceptible to the attack of D. melacanthus, and the greatest yield reduction occurred from stem elongation (26.5%) to milky grain stage (33.1%). Seed treatment using insecticides was efficient, greatly reducing the grain production losses.

Resultados de avaliações de campo indicaram que o pentatomídeo neotropical Dichelops melacanthus (Dallas) está associado ao trigo, Triticum aestivum L. Em sistema de plantio direto, ninfas e adultos foram encontrados principalmente no solo, próximos aos caules das plantas e sob restos da cultura de verão precedente, em geral, soja, Glycine max (L.) Merrill, ou milho, Zea mays L. Em trigo sob cultivo convencional observou-se incidência mínima dos percevejos. D. melacanthus causou danos substanciais em trigo sob plantio direto, atacando particularmente plantas jovens (plântulas), provocando redução de até 34% no número de espigas e de 31% no peso de grãos. Todas as fases do desenvolvimento da planta do trigo foram suscetíveis ao ataque de D. melacanthus, sendo que a maior redução no rendimento ocorreu devido à ação dos percevejos do alongamento dos caules (26,5%) ao estágio de grão leitoso (33,1%). O tratamento de sementes com inseticidas foi eficiente para evitar a perda de rendimento de grãos.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): Antônio R. Panizzi

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
damage/losses/economics

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Dichelops melacanthus	Maize/corn (Zea mays)
	Dichelops melacanthus	Wheat (Triticum)	Brazil (south)